kona resident here.
1> Nearest plate lunch place is at the top of kaiminani. Its called Kays kitchen. Open from 7am-7pm. Second closest, Hina lani industrial area. Rainbow Cafe. Top of the area, near costco. Chinese and plate lunch dishes closes at 8pm.
2> Dennys in town has free wireless internet. Ive never gotten any wireless access in the airport but i do believe Avis has Wireless access. Since i never rent from that avis location, i dont know what kind of facilities they have there. Someone also told me Herz has access at their location. Once again, I dont rent there so I cannot confirm.
The airport itself has very limited food options. Just the maxwells landing bar and cafe inside the airport itself.
3> If you have at least 5 hours to kill. Id suggest dinner at merrimans market cafe at the kings shops waikoloa. Next best choice would be buffet at King Kam (seafood). you could do the big island grill thing, nothing wrong with that route. Might I suggest the roast pork or roast turkey plate. Renting a car to go to dinner anywhere is a treat. You can eat dinner on alii drive and watch the sunset.
4> K mart is slightly closer to the airport than town, and it has the requisite little caesars (pizza pizza).
When I fly out on the redeye flights, the bulk of the peeps arrive around 8pm. Traffic into town from the airport is about 45 minutes (southbound) and northbound around 8pm isnt an issue. If you head waikoloa way, its 30-45 min to kings shops and predominately against traffic flow so its an easy drive. by the time 8pm rolls along, the traffic is over with.
Kona suggestions for food, period listed in no special order.
1> King Kam Hotel's Buffet. alii drive
2> Merrimans Market Cafe Kings shops
3> Big island grill (inexpensive-ish) Kuakini highway (near alii drive)
4> Big Island Steak house (I always liked the oahu one better) waikoloa
5> Roys (waikoloa)
6> Drysdale too (bar grill keahou shopping center)
7> Quinns (across from king kam) best fish and chips on the island. a local favorite.
8> Wendys. Near alii drive.
9> Dennys. Henry st by wal mart and safeway. THE ONLY 24 HOUR OPTION in town. If you arrive late, or your flight is massively delayed, this is your only option aside from safeway or walmart snack raids.
10> Pizza Hut, near wendys.
11> Subway and quiznos. Henry St
12> Jamba Juice and Starbucks Henry st AND near wendys.
13> Mcdonalds, inside walmart and Kuakini Highway.
That should give anyone some options if stranded
Incidenttaly-cars at the kona airport are usually had for 30-40 dollars. Taxi to Waikoloa is 50 bucks. Taxi to alii drive is 25 and up. Also, check when the car rental place closes. Ive come in on flights and seen rental counters closed for late arrivals, but I have never needed to return a car to this airport so i dont know when their check in closes. I suggest asking.